To harvest peanuts, it is conventional practice to first dig the peanuts from the ground and to allow the peanuts and associated crop material to lie about the ground where over a period of time the peanuts tend to dry. After this, a peanut harvester moves through the field where a front mounted pick-up reel engages the lying crop material and the associated peanuts and delivers the same into the peanut harvester or combine where the peanuts are separated from the above ground crop material, vines and roots, etc.
It has been conventional to drive the pick-up reel of a peanut combine at a constant speed irrespective of the ground speed of the harvester or the density of the crop. Thus, in such case there is no correlation between the ground speed of the peanut combine and the pick-up reel and this often results in the pick-up reel jerking and snatching the peanut crop material and the peanuts being jarred from the root structure of the plant prior to entering the combine. This, of course, gives rise to what is termed "field losses".
Also, it should be pointed out that in the case of a constant speed pick-reel that it is possible to overload the combine in areas where the crop material is relatively dense and the speed of the combine is not altered so as to reduce the load during the harvesting operation. The continuous overloading of the combine will naturally wear the internal structure of the combine and will generally decrease the life of the internal thrashing and harvesting components of the combine. In addition, the overloading of the combine can result in actual clogging and the possibility that such an overload will damage or break certain internal components of the combine.